latest changes

AGENTS.md

@@ -22,7 +22,8 @@ This project builds a presentation deck for Marp based on Markdown files.
 
 ### File Structure
 - Use `slides/` directory for Markdown slide files
-- Use `assets/` for images and media files
+- Use `assets/` directory for images and media files
+- Always address images as ./assets/filename.png, not assets/ or ../assets/
 - Use `themes/` for custom Marp themes
 - Use `build/` directory for generated output files (ignored by git)